1. Technical Field
The present disclosure relates to a hybrid vehicle.
2. Description of Related Art
Conventionally, there is suggested a hybrid vehicle (see, for example, Japanese Patent Application Publication No. 2013-147193 (JP 2013-147193 A). In this hybrid vehicle, a first rotary electric machine is connected to a sun gear of a planetary gear, an engine is connected to a carrier, a drive shaft is connected to a ring gear, a second rotary electric machine is connected to the drive shaft, a one-way clutch is connected to the carrier and a battery is electrically connected to the first rotary electric machine and the second rotary electric machine. The hybrid vehicle selectively travels in EV drive mode or HV drive mode in charge depleting (CD) mode or charge sustaining (CS) mode. The CD mode is, for example, a mode in which consumption of electric power of the battery is permitted, and is selected when a state of charge of the battery is higher than or equal to a threshold. The CS mode is, for example, a mode in which the state of charge of the battery is kept within a certain range, and is selected when the state of charge of the battery is lower than the threshold. The EV drive mode is a mode in which the hybrid vehicle travels by using at least one of the first rotary electric machine and the second rotary electric machine as a power source. The EV drive mode includes a single-drive mode and a double-drive mode. In the single-drive mode, only the second rotary electric machine is used as a power source. In the double-drive mode, the first rotary electric machine and the second rotary electric machine are used as power sources. The HV drive mode is a mode in which the hybrid vehicle travels by using the engine as a power source.
A hybrid vehicle, particularly, a plug-in hybrid vehicle, basically travels in the EV drive mode and, when a required output (torque, power) for propelling the hybrid vehicle is relatively large, shifts into the HV drive mode to meet the required output. When the hybrid vehicle shifts from the EV drive mode to the HV drive mode, the hybrid vehicle is required to start the engine, so it is inconvenient that it takes a certain time until the engine functions as a power source.